Variable Refrigerant Flow/Volume (VRF/VRV)(101)
Variable Refrigerant Flow/Volume (VRF/VRV) products updated recently
Building owners and specifiers can experience design flexibility, reduced operational costs and reliable, energy-efficient comfort year-round with Variable Refrigerant Flow (VRF) systems, even in extreme cold climates. Modern VRF systems like those from Mitsubishi Electric Trane HVAC US far exceed the capabilities of conventional heat pumps at low outdoor ambient temperatures and are in a great position to replace fossil fuel burning equipment in almost any climate. The Fundamentals of VRF Systems VRF technology consolidates heating and cooling into one VRF technology consolidates heating and cooling into one, all-electric system. Improving on the direct-expansion (DX) principle, a VRF system uses linear expansion valves (LEV) and an INVERTER-driven compressor to cycle refrigerant and transfer heat between its outdoor unit and the indoor unit(s) in each zone. Continuous communication between the system’s outdoor units, indoor units, sensors and controls allow VRF systems to modulate capacity based on loads and occupancy. With precise management of capacity, VRF systems reliably maintain each zone’s set point without the noisy and energy-intensive start/stop cycles of conventional systems. Design Considerations for Low-Ambient Heating The reliable performance and energy efficiency of modern VRF systems aren’t solely the product of superior product engineering. Accurate load calculations, proper installation, diligent commissioning, and regular maintenance, are essential for success. Let’s discuss six options HVAC contractors and engineers can use to solve derating challenges, even in climate zones 5 and 6. HVAC contractors can solve challenges, even in extreme climate zones Options for Solving Derating Challenges With VRF flash-injection technology, as long as an air-source heat pump can make its refrigerant cooler than the outdoor air, thermal energy can be extracted and delivered to interior zones as heat. In extreme cold, the compressor needs to operate at speeds much higher than usual to drive the refrigerant temperature and pressure in the condenser coil sufficiently low to capture ambient heat. With flash-injection technology, a VRF system injects a small amount of mixed-phase refrigerant to cool the compressor, allowing it to perform at higher speeds without failing due to friction and heat build-up. This method enables VRF systems to deliver significant heat at low temperatures. For example, CITY MULTI® VRF systems with Hyper-Heating INVERTER® (H2i®) technology can provide up to 100 percent of heating capacity down to -4° F, up to 70 percent of heating capacity down to -22° F and continuous heating at temperatures as low as -31° F. Flash-injection technology creates the opportunity to size units based upon heating loads and use the VRF system as a sole source for heating. In most regions, changeover to auxiliary heating sources is rarely needed, but can be easily accomplished with built in controls if an existing heating system is already in place. Auxiliary or backup heat can be provided by a system that generates heat using a method such as electric resistance, baseboard hydronic wall-fin radiant heat or duct coils mounted downstream of an air handler. Auxilliary or back-up heat may be installed with the VRF system while others might be an older existing system, such as a gas-fired hydronic boiler a facility repurposes after a retrofit. Due to greater efficiency, the VRF system typically provides the first stage of heat. Sole-source sizing based on heating is an alternative to using a flash-injection product, employing the option to oversize standard VRF systems for heating capacity. Specifiers must be mindful of heating derates as found in the VRF manufacturer’s selection software or engineering manuals when using this method. Designers will likely need to oversize the indoor units as well as the outdoor unit. Otherwise, the indoor units will be unable to use the extra capacity. Oversizing VRF systems to meet heating capacity should be limited to 25 percent or less so that the system doesn’t end up being excessively oversized for the commensurate cooling load. Oversize DOAS heat. VRF systems are often used in conjunction with complementary systems for ventilation. A dedicated outdoor air system (DOAS) is typically designed to supply room-neutral air (between 70° F and 75° F) in the heating mode but could be upsized to provide additional heat. With the use of a recirculation air damper and an upsized heat source (gas, hot water or electric), the oversized DOAS could be used for emergency heat or morning warmup during winter. Install outdoor units inside the building to limit derating and weather impacts in severe cold regions. In this scenario, air-source condensers are installed in a mechanical room that serves as a recirculation air plenum or a pass-through air plenum, depending on the outdoor temperature. When the auxiliary heat runs, the VRF system’s efficiency approaches the efficiency of the backup system. If the unit heater is 80% efficient, the overall system efficiency will drop so the backup unit heaters that heat the mechanical room should only run at colder temperatures. While this approach can be expensive due to the number of dampers and louvers required, the design allows a facility to locate auxiliary heat in a central location, the mechanical room. Water-source VRF systems are available as heat pumps or with heat recovery. With water-source VRF systems, all of the equipment is designed to be installed indoors. They deliver greater efficiency and have less derating versus air-source VRF systems. Less energy is needed to extract heat or reject heat into or out of water, as compared to air due to the density of each of these mediums. Also, a water loop offers a more defined and controlled temperature range, generally between 60° F and 90° F. The capacity of a water-source system is based on entering water temperature. VRF Systems Provide Comfort in Any Climate When applied according to best practices and with consideration for winter weather, modern VRF systems can serve as the primary heating and cooling system even in the coldest climates. With flash-injection compressor technology and water-source options, VRF systems offer cold-climate capabilities far beyond those of conventional heat pump systems, even without auxiliary heat.
As a Managing Director of a company that provides temperature and humidity solutions to predominantly the warehousing and industrial sectors, I thought I would share my dilemma that I’m sure other business owners and managers also face. I don’t pretend to know the answers, but thought it might be worth sharing some of the considerations that I’m facing in whether to reshape, recruit and build or hunker down until the World, Europe and the UK offers some sort or predictability. I promise to not refer to ‘new normal’, masks or social distancing as this is extensively covered elsewhere. Context Our business has seen steady growth in the past 5 years, as a result of our efforts to create and retain relationships with customers who value our offer. Our focus has always been to offer solutions to large scale complex HVAC projects. We invest heavily in intellectual talent sponsoring PhD and MSc students, to keep us on our toes and develop leading edge solutions. We also feed off each other and our network of equally talented suppliers. My dilemma as Managing Director is do I continue our ambitious Research & Development (R&D), IP and Business Development or throttle back and take a cautionary approach until the economy offers a more certain platform? ‘Fortune favors the brave’ they say, but when you have a good business and employees look to business managers to ensure their livelihoods, how brave is brave? The Dilemma Immediate transactional or contractor resources are easy to obtain with the right screening and due diligence Immediate transactional or contractor resources are relatively easy to obtain with the right screening and due diligence, but for more developmental strategic roles, do you recruit in an emerging post pandemic, catastrophic employment forecast, that to in a mid/post Brexit world? From my personal perspective, it boils down to attitude, communication, enthusiasm and buy-in from everyone in the company. Nothing new there, but it feels that the stakes are higher so confidence is key. Do we or don’t we? Inaction is the riskiest response to the uncertainties of an economic crisis. Rash or scattershot action can be nearly as damaging. Rising anxiety (How much worse are things likely to get? and for how long is this going to last?) and the growing pressure to do something often produces a variety of moves that target the wrong problem or overshoot the right one. Within the world of HVAC, changes to legislation, environmental considerations, technological changes and research and development might be slowed or influenced, but won’t stop as a consequence of the immediate economy, which is a good thing. Recruiting on a need basis Many companies recruit when needed, to fill a vacant position or when a large project demands more manpower than the current headcount supports. This approach is obvious and addresses immediate transactional and resource needs. Using headcount as a KPI for growth, at a glimpse may illustrate positivity, but may be signaling a stop gap and may not be a true indicator of strategic growth. Of all the things I have observed over the last 5 months, reading the news, talking to colleagues and peers, a few things have stuck out for me, such as how companies have treated their employees, customers and suppliers, how creative and flexible some big organizations have been in responding to market changes and demands and how, despite uncertainty, their core business skills, intelligence and ability enabled them to prosper in a new and unforeseen environment. Finally, how companies will be remembered post crisis. Robust business planning The ability to respond quickly to market changes relies on creativity and attitude My belief is that those companies that have and continue to float to the top had the key ingredients of a successful business, enabled by capable enthusiastic talent that were given the opportunity to shine. These people weren’t hired to fill a stop gap, but rather these people were hired as part of a robust business plan. So, ‘do we or don’t we?’ Our philosophy at Jet Environmental Systems is to have a solid platform, identify future markets, trends and technologies and hire the absolute best people that we can to get us there. Recruitment in our business is a process that supports our strategic development and so for us our answer is yes, have confidence and continue to invest in the best talent. The ability to respond quickly to market changes relies on creativity and attitude with support from equally enthusiastic management who create the opportunity for individuals who present this talent to grow. Conclusion I hope the thought process I’ve shared has been useful, for me it has been a checkpoint in whether our choice of investment in people is right, not just now but in all situations. For me, it’s a resounding yes! I think we will create opportunities by having vision and giving people opportunity.
Residential HVAC is a fulfilling business to be in. Whether be it servicing a furnace or installing an air conditioning unit, the individual is doing important work to help keep families in the community safe and comfortable. The work also comes with perks such as good margins, some great customers, and the ability to set varying pricing and schedule. If an individual is in a growing business in this space, chances are that they have seen more than a few hectic days. Days where it becomes difficult to juggle crews, instruct technicians on necessary job details, and answer client calls, all at the same time. In theory, this chaotic day-to-day is a good problem to have. In practice, it can get really tiring, pretty fast. Robust system to streamline operations The work can be extremely overwhelming and if the right systems aren’t in place, the business could suffer. Lines of communication can get crossed and if time is being spent working on the wrong things, the individual could miss out on opportunities to grow. While there is no one-size-fits-all approach to managing a high growth HVAC business, by applying the right operational strategies, businesses can flourish. Coordinating requests while dispatching techs out to do work is where many administrators and operations managers hit a roadblock in business growth. This is precisely why businesses need to implement software that lets them track jobs, view technician schedules, and flag new jobs to crew members all in one place. This will eliminate the need to play ‘phone tag’ across the organization, which in turn will keep operations running smoothly and reduce manual errors. What’s more, if the software allows techs to automatically trigger an invoice that customers can pay on the spot, businesses can avoid hours of chasing down past-due payments and create a better cash flow. mobile apps: Picking The right software Businesses are encouraged to choose software with a mobile app where customers can enter the payment type Businesses are encouraged to choose software with a mobile app where customers can enter the payment type, such as cash, check, credit, debit and a receipt can be automatically emailed to customers. This will also cut out out-of-date operations, while giving businesses access to what they need (schedules, work orders, customer information and more) at anytime from anywhere. Having a central hub for keeping everything organized also creates the operational flexibility needed to take on work. To ensure businesses don’t have to turn new jobs down due to delayed responses or scheduling issues, a crew member can be kept flexible for this task. In order to do this right, businesses need to calculate how much emergency work they’re losing due to unavailability and adjust accordingly, by creating a schedule with allotted time. Spacing out work won’t impact the number of scheduled installs and replacements retained, while giving businesses added time and revenue to take on emergency repairs. This strategy is only doable if businesses have the requisite software that can provide an accurate and full look into employees’ workloads. pricing services Research Is Important A business in high-growth mode needs to ensure their pricing reflects the services being offered. This can be done with researching of other companies in the area that are charging for the same services offered, so that the business can have a number to compare to when setting prices and also prepare to justify higher price to customers. Setting prices higher can be advantageous for a business, if they can show customers the differentiators. Most people want work done right, and an added premium that ensures top service often won’t turn them away. Additionally, it’s important to make sure all expenses are covered, down to the credit card fees. When pricing services, businesses need to build a file of overhead expenses, then determine the percentage profit want to charge clients. Different jobs require unique services, so prices should reflect that Varied pricing per customer Different jobs require unique services, so prices should reflect that. A business might charge more for commercial clients than homeowners. These minor adjustments will ensure that a business makes the profit that the work deserves. Feedback is also very important for repeat orders. If a business is not getting repeat clients due to pricing, they should keep that in mind when building profit margins. Pricing shouldn’t be static, continuous adjustments has to be made where it makes sense and extra time invested to do the research. Ensuring exceptional customer service It’s important to set up systems and expectations for teams to follow right out of the gate With business growth also comes customer growth, and for residential HVAC companies that physically go into a customer’s home, it’s crucial that their services reflect the highest quality. It’s important to set up systems and expectations for teams to follow right out of the gate. Helping crews do their best work from a technical and customer service perspective by establishing guidelines for what the business wants every homeowner to experience is the key. Open lines of communication Aside from ensuring that the crew keeps a clean workplace, keeping open lines of communication with customers should be a top priority for businesses. This can be as simple as answering the phone and getting a technician to a job site as soon as possible. Often, customers come from positions of stress due to broken equipment, so having quick response time is a key differentiator between good and bad service. A good solution for this is to evolve into automating key communications that allow techs to send ‘on my way’ text messages. How a business interacts with customers is a key signifier into how the company operates, so businesses need to ensure that have the best customer service practices in place. Never take valuable employees for granted While it sounds simple, a high-growth business needs reliable employees to scale, so that their competition does not swoop in and scoop up an employee who doesn’t feel valued. As business ramps up, it’s easy to miss that technicians are not being dispatched to jobs that they enjoy. If employees are constantly doing a job because they’re good at it and they don’t feel fulfilled doing that specific job, at the end of the day, they are not going to be happy. To avoid losing employees, businesses should take the time to ask what jobs they like to do and see if they can accommodate schedules to reflect their preferences. employee retention And loyalty A crucial factor in building a top performing team is employee retention and loyalty A crucial factor in building a top performing team is employee retention and loyalty. Businesses should focus on creating a great atmosphere to work in. This includes keeping a pulse on what’s happening in the team’s personal lives and use that to show appreciation in meaningful ways. One way to do this is by investing in the team’s education. For example, paying tuition fees for techs so they can get new certifications and licensing. These types of gestures show that the business cares about the success of their employees, while also helping them retain the most qualified crew members. Incorporating software solutions and automating tedious tasks Developing a high-growth residential HVAC company doesn’t have to be stressful if businesses know what systems and processes to implement to better manage operations. By adopting strategies that incorporate software solutions, like Jobber, to streamline operations, automate tedious tasks and improve customer communications, the opportunity for growth is more accessible for businesses. Organizations should focus on creating a solid operational system by doing research before pricing services, keeping customer service a top priority and not letting great employees slip away. All these strategies will work together to help maximize business growth.